His firing came about six months before North and Central American and Caribbean World Cup qualifying, which takes place from Oct. 16-26 at Cancun and Playa del Carmen, Mexico.
On Sunday, Sermanni experimented with a 4-3-3 alignment (four defenders, three midfielders and three forwards) and talked about the team making the most of its offensive opportunities.
"I thought our movement was good, thought our passing was quite incisive," Sermanni said. "What we should've done better is finish the game off a lot earlier. We really need to be finishing these games off when we're creating chances."
The U.S. outshot China 23-1 and ran its unbeaten streak on home turf to 81 games (71-0-10).
Holiday was back in the lineup after missing the Algarve Cup because of a family commitment. She scored in the 39th minute — the U.S. finally solving goalkeeper Zhang Yue after a flurry of shots. Holiday nearly had another goal early in the second half, only to have it deflected near the goal line.
The defense allowed only one scoring chance to China, which played defensively even after falling behind.
"The most important thing is coming together now and figuring out what works and what doesn't," forward Sydney Leroux said. "We're getting better every single day."
Any further improvement will come under a new coach.